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iso_of_components (H : X.1 ≅ Y.1) (α : H.hom _* X.2 ≅ Y.2) : X ≅ Y
{ hom := { base := H.hom, c := α.inv }, inv := { base := H.inv, c := presheaf.to_pushforward_of_iso H α.hom }, hom_inv_id' := by { ext, { simp, erw category.id_comp, simpa }, simp }, inv_hom_id' := begin ext x, induction x using opposite.rec, simp only [comp_c_app, whisker_right_app, presheaf.to...
def
algebraic_geometry.PresheafedSpace.iso_of_components
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[ "opposite.rec" ]
An isomorphism of PresheafedSpaces is a homeomorphism of the underlying space, and a natural transformation between the sheaves.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sheaf_iso_of_iso (H : X ≅ Y) : Y.2 ≅ H.hom.base _* X.2
{ hom := H.hom.c, inv := presheaf.pushforward_to_of_iso ((forget _).map_iso H).symm H.inv.c, hom_inv_id' := begin ext U, have := congr_app H.inv_hom_id U, simp only [comp_c_app, id_c_app, eq_to_hom_map, eq_to_hom_trans] at this, generalize_proofs h at this, simpa using congr_arg (λ f, f ...
def
algebraic_geometry.PresheafedSpace.sheaf_iso_of_iso
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
Isomorphic PresheafedSpaces have natural isomorphic presheaves.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
base_is_iso_of_iso (f : X ⟶ Y) [is_iso f] : is_iso f.base
is_iso.of_iso ((forget _).map_iso (as_iso f))
instance
algebraic_geometry.PresheafedSpace.base_is_iso_of_iso
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
c_is_iso_of_iso (f : X ⟶ Y) [is_iso f] : is_iso f.c
is_iso.of_iso (sheaf_iso_of_iso (as_iso f))
instance
algebraic_geometry.PresheafedSpace.c_is_iso_of_iso
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_of_components (f : X ⟶ Y) [is_iso f.base] [is_iso f.c] : is_iso f
begin convert is_iso.of_iso (iso_of_components (as_iso f.base) (as_iso f.c).symm), ext, { simpa }, { simp }, end
lemma
algebraic_geometry.PresheafedSpace.is_iso_of_components
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
This could be used in conjunction with `category_theory.nat_iso.is_iso_of_is_iso_app`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict {U : Top} (X : PresheafedSpace.{v v u} C) {f : U ⟶ (X : Top.{v})} (h : open_embedding f) : PresheafedSpace C
{ carrier := U, presheaf := h.is_open_map.functor.op ⋙ X.presheaf }
def
algebraic_geometry.PresheafedSpace.restrict
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[ "Top", "open_embedding" ]
The restriction of a presheafed space along an open embedding into the space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_restrict {U : Top} (X : PresheafedSpace.{v v u} C) {f : U ⟶ (X : Top.{v})} (h : open_embedding f) : X.restrict h ⟶ X
{ base := f, c := { app := λ V, X.presheaf.map (h.is_open_map.adjunction.counit.app V.unop).op, naturality' := λ U V f, show _ = _ ≫ X.presheaf.map _, by { rw [← map_comp, ← map_comp], refl } } }
def
algebraic_geometry.PresheafedSpace.of_restrict
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[ "Top", "map_comp", "open_embedding" ]
The map from the restriction of a presheafed space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_restrict_mono {U : Top} (X : PresheafedSpace C) (f : U ⟶ X.1) (hf : open_embedding f) : mono (X.of_restrict hf)
begin haveI : mono f := (Top.mono_iff_injective _).mpr hf.inj, constructor, intros Z g₁ g₂ eq, ext V, { induction V using opposite.rec, have hV : (opens.map (X.of_restrict hf).base).obj (hf.is_open_map.functor.obj V) = V, { ext1, exact set.preimage_image_eq _ hf.inj }, haveI : is_iso (hf.i...
instance
algebraic_geometry.PresheafedSpace.of_restrict_mono
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[ "Top", "Top.mono_iff_injective", "open_embedding", "opposite.rec", "set.preimage_image_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_top_presheaf (X : PresheafedSpace C) : (X.restrict (opens.open_embedding ⊤)).presheaf = (opens.inclusion_top_iso X.carrier).inv _* X.presheaf
by { dsimp, rw opens.inclusion_top_functor X.carrier, refl }
lemma
algebraic_geometry.PresheafedSpace.restrict_top_presheaf
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_restrict_top_c (X : PresheafedSpace C) : (X.of_restrict (opens.open_embedding ⊤)).c = eq_to_hom (by { rw [restrict_top_presheaf, ←presheaf.pushforward.comp_eq], erw iso.inv_hom_id, rw presheaf.pushforward.id_eq })
/- another approach would be to prove the left hand side is a natural isoomorphism, but I encountered a universe issue when `apply nat_iso.is_iso_of_is_iso_app`. -/ begin ext U, change X.presheaf.map _ = _, convert eq_to_hom_map _ _ using 1, congr, simpa, { induction U using opposite.rec, dsimp, congr, ...
lemma
algebraic_geometry.PresheafedSpace.of_restrict_top_c
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[ "opposite.rec" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_restrict_top (X : PresheafedSpace C) : X ⟶ X.restrict (opens.open_embedding ⊤)
{ base := (opens.inclusion_top_iso X.carrier).inv, c := eq_to_hom (restrict_top_presheaf X) }
def
algebraic_geometry.PresheafedSpace.to_restrict_top
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
The map to the restriction of a presheafed space along the canonical inclusion from the top subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_top_iso (X : PresheafedSpace C) : X.restrict (opens.open_embedding ⊤) ≅ X
{ hom := X.of_restrict _, inv := X.to_restrict_top, hom_inv_id' := ext _ _ (concrete_category.hom_ext _ _ $ λ ⟨x, _⟩, rfl) $ by { erw comp_c, rw X.of_restrict_top_c, ext, simp }, inv_hom_id' := ext _ _ rfl $ by { erw comp_c, rw X.of_restrict_top_c, ext, simpa [-eq_to_hom_refl] } }
def
algebraic_geometry.PresheafedSpace.restrict_top_iso
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
The isomorphism from the restriction to the top subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Γ : (PresheafedSpace.{v v u} C)ᵒᵖ ⥤ C
{ obj := λ X, (unop X).presheaf.obj (op ⊤), map := λ X Y f, f.unop.c.app (op ⊤) }
def
algebraic_geometry.PresheafedSpace.Γ
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
The global sections, notated Gamma.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Γ_obj_op (X : PresheafedSpace C) : Γ.obj (op X) = X.presheaf.obj (op ⊤)
rfl
lemma
algebraic_geometry.PresheafedSpace.Γ_obj_op
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Γ_map_op {X Y : PresheafedSpace.{v v u} C} (f : X ⟶ Y) : Γ.map f.op = f.c.app (op ⊤)
rfl
lemma
algebraic_geometry.PresheafedSpace.Γ_map_op
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_presheaf (F : C ⥤ D) : PresheafedSpace.{v v u} C ⥤ PresheafedSpace.{v v u} D
{ obj := λ X, { carrier := X.carrier, presheaf := X.presheaf ⋙ F }, map := λ X Y f, { base := f.base, c := whisker_right f.c F }, }
def
category_theory.functor.map_presheaf
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
We can apply a functor `F : C ⥤ D` to the values of the presheaf in any `PresheafedSpace C`, giving a functor `PresheafedSpace C ⥤ PresheafedSpace D`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_presheaf_obj_X (F : C ⥤ D) (X : PresheafedSpace C) : ((F.map_presheaf.obj X) : Top.{v}) = (X : Top.{v})
rfl
lemma
category_theory.functor.map_presheaf_obj_X
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_presheaf_obj_presheaf (F : C ⥤ D) (X : PresheafedSpace C) : (F.map_presheaf.obj X).presheaf = X.presheaf ⋙ F
rfl
lemma
category_theory.functor.map_presheaf_obj_presheaf
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_presheaf_map_f (F : C ⥤ D) {X Y : PresheafedSpace.{v v u} C} (f : X ⟶ Y) : (F.map_presheaf.map f).base = f.base
rfl
lemma
category_theory.functor.map_presheaf_map_f
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_presheaf_map_c (F : C ⥤ D) {X Y : PresheafedSpace.{v v u} C} (f : X ⟶ Y) : (F.map_presheaf.map f).c = whisker_right f.c F
rfl
lemma
category_theory.functor.map_presheaf_map_c
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
on_presheaf {F G : C ⥤ D} (α : F ⟶ G) : G.map_presheaf ⟶ F.map_presheaf
{ app := λ X, { base := 𝟙 _, c := whisker_left X.presheaf α ≫ eq_to_hom (presheaf.pushforward.id_eq _).symm } }
def
category_theory.nat_trans.on_presheaf
algebraic_geometry
src/algebraic_geometry/presheafed_space.lean
[ "topology.sheaves.presheaf", "category_theory.adjunction.fully_faithful" ]
[]
A natural transformation induces a natural transformation between the `map_presheaf` functors.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_reduced : Prop
(component_reduced : ∀ U, _root_.is_reduced (X.presheaf.obj (op U)) . tactic.apply_instance)
class
algebraic_geometry.is_reduced
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_reduced" ]
A scheme `X` is reduced if all `𝒪ₓ(U)` are reduced.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_reduced_of_stalk_is_reduced [∀ x : X.carrier, _root_.is_reduced (X.presheaf.stalk x)] : is_reduced X
begin refine ⟨λ U, ⟨λ s hs, _⟩⟩, apply presheaf.section_ext X.sheaf U s 0, intro x, rw ring_hom.map_zero, change X.presheaf.germ x s = 0, exact (hs.map _).eq_zero end
lemma
algebraic_geometry.is_reduced_of_stalk_is_reduced
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_reduced", "ring_hom.map_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stalk_is_reduced_of_reduced [is_reduced X] (x : X.carrier) : _root_.is_reduced (X.presheaf.stalk x)
begin constructor, rintros g ⟨n, e⟩, obtain ⟨U, hxU, s, rfl⟩ := X.presheaf.germ_exist x g, rw [← map_pow, ← map_zero (X.presheaf.germ ⟨x, hxU⟩)] at e, obtain ⟨V, hxV, iU, iV, e'⟩ := X.presheaf.germ_eq x hxU hxU _ 0 e, rw [map_pow, map_zero] at e', replace e' := (is_nilpotent.mk _ _ e').eq_zero, erw ← co...
instance
algebraic_geometry.stalk_is_reduced_of_reduced
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_nilpotent.mk", "is_reduced", "map_pow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_reduced_of_open_immersion {X Y : Scheme} (f : X ⟶ Y) [H : is_open_immersion f] [is_reduced Y] : is_reduced X
begin constructor, intro U, have : U = (opens.map f.1.base).obj (H.base_open.is_open_map.functor.obj U), { ext1, exact (set.preimage_image_eq _ H.base_open.inj).symm }, rw this, exact is_reduced_of_injective (inv $ f.1.c.app (op $ H.base_open.is_open_map.functor.obj U)) (as_iso $ f.1.c.app (op $ H.base_...
lemma
algebraic_geometry.is_reduced_of_open_immersion
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_reduced", "is_reduced_of_injective", "set.preimage_image_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
affine_is_reduced_iff (R : CommRing) : is_reduced (Scheme.Spec.obj $ op R) ↔ _root_.is_reduced R
begin refine ⟨_, λ h, by exactI infer_instance⟩, intro h, resetI, haveI : _root_.is_reduced (LocallyRingedSpace.Γ.obj (op $ Spec.to_LocallyRingedSpace.obj $ op R)), { change _root_.is_reduced ((Scheme.Spec.obj $ op R).presheaf.obj $ op ⊤), apply_instance }, exact is_reduced_of_injective (to_Spec_Γ R) ((...
lemma
algebraic_geometry.affine_is_reduced_iff
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "CommRing", "is_reduced", "is_reduced_of_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_reduced_of_is_affine_is_reduced [is_affine X] [h : _root_.is_reduced (X.presheaf.obj (op ⊤))] : is_reduced X
begin haveI : is_reduced (Scheme.Spec.obj (op (Scheme.Γ.obj (op X)))), { rw affine_is_reduced_iff, exact h }, exact is_reduced_of_open_immersion X.iso_Spec.hom, end
lemma
algebraic_geometry.is_reduced_of_is_affine_is_reduced
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_reduced" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reduce_to_affine_global (P : ∀ (X : Scheme) (U : opens X.carrier), Prop) (h₁ : ∀ (X : Scheme) (U : opens X.carrier), (∀ (x : U), ∃ {V} (h : x.1 ∈ V) (i : V ⟶ U), P X V) → P X U) (h₂ : ∀ {X Y} (f : X ⟶ Y) [hf : is_open_immersion f], ∃ {U : set X.carrier} {V : set Y.carrier} (hU : U = ⊤) (hV : V = set.range f...
begin intros X U, apply h₁, intro x, obtain ⟨_, ⟨j, rfl⟩, hx, i⟩ := X.affine_basis_cover_is_basis.exists_subset_of_mem_open (set_like.mem_coe.2 x.prop) U.is_open, let U' : opens _ := ⟨_, (X.affine_basis_cover.is_open j).base_open.open_range⟩, let i' : U' ⟶ U := hom_of_le i, refine ⟨U', hx, i', _⟩,...
lemma
algebraic_geometry.reduce_to_affine_global
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "CommRing", "set.range" ]
To show that a statement `P` holds for all open subsets of all schemes, it suffices to show that 1. In any scheme `X`, if `P` holds for an open cover of `U`, then `P` holds for `U`. 2. For an open immerison `f : X ⟶ Y`, if `P` holds for the entire space of `X`, then `P` holds for the image of `f`. 3. `P` holds for th...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reduce_to_affine_nbhd (P : ∀ (X : Scheme) (x : X.carrier), Prop) (h₁ : ∀ (R : CommRing) (x : prime_spectrum R), P (Scheme.Spec.obj $ op R) x) (h₂ : ∀ {X Y} (f : X ⟶ Y) [is_open_immersion f] (x : X.carrier), P X x → P Y (f.1.base x)) : ∀ (X : Scheme) (x : X.carrier), P X x
begin intros X x, obtain ⟨y, e⟩ := X.affine_cover.covers x, convert h₂ (X.affine_cover.map (X.affine_cover.f x)) y _, { rw e }, apply h₁, end
lemma
algebraic_geometry.reduce_to_affine_nbhd
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "CommRing", "prime_spectrum" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_of_basic_open_eq_bot {X : Scheme} [hX : is_reduced X] {U : opens X.carrier} (s : X.presheaf.obj (op U)) (hs : X.basic_open s = ⊥) : s = 0
begin apply Top.presheaf.section_ext X.sheaf U, simp_rw ring_hom.map_zero, unfreezingI { revert X U hX s }, refine reduce_to_affine_global _ _ _ _, { intros X U hx hX s hs x, obtain ⟨V, hx, i, H⟩ := hx x, unfreezingI { specialize H (X.presheaf.map i.op s) }, erw Scheme.basic_open_res at H, rw ...
lemma
algebraic_geometry.eq_zero_of_basic_open_eq_bot
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "Top.presheaf.section_ext", "inf_bot_eq", "is_nilpotent.eq_zero", "is_reduced", "prime_spectrum.basic_open_eq_bot_iff", "ring_hom.map_zero", "set.image_univ", "set.preimage_image_eq", "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
basic_open_eq_bot_iff {X : Scheme} [is_reduced X] {U : opens X.carrier} (s : X.presheaf.obj $ op U) : X.basic_open s = ⊥ ↔ s = 0
begin refine ⟨eq_zero_of_basic_open_eq_bot s, _⟩, rintro rfl, simp, end
lemma
algebraic_geometry.basic_open_eq_bot_iff
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_reduced" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_integral : Prop
(nonempty : nonempty X.carrier . tactic.apply_instance) (component_integral : ∀ (U : opens X.carrier) [_root_.nonempty U], is_domain (X.presheaf.obj (op U)) . tactic.apply_instance)
class
algebraic_geometry.is_integral
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_domain", "is_integral" ]
A scheme `X` is integral if its carrier is nonempty, and `𝒪ₓ(U)` is an integral domain for each `U ≠ ∅`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_reduced_of_is_integral [is_integral X] : is_reduced X
begin constructor, intro U, cases U.1.eq_empty_or_nonempty with h h, { have : U = ⊥ := set_like.ext' h, haveI := CommRing.subsingleton_of_is_terminal (X.sheaf.is_terminal_of_eq_empty this), change _root_.is_reduced (X.sheaf.val.obj (op U)), apply_instance }, { haveI : nonempty U := by simpa, apply...
instance
algebraic_geometry.is_reduced_of_is_integral
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "CommRing.subsingleton_of_is_terminal", "is_integral", "is_reduced", "set_like.ext'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_irreducible_of_is_integral [is_integral X] : irreducible_space X.carrier
begin by_contradiction H, replace H : ¬ is_preirreducible (⊤ : set X.carrier) := λ h, H { to_preirreducible_space := ⟨h⟩, to_nonempty := infer_instance }, simp_rw [is_preirreducible_iff_closed_union_closed, not_forall, not_or_distrib] at H, rcases H with ⟨S, T, hS, hT, h₁, h₂, h₃⟩, erw not_forall at h₂ h₃...
instance
algebraic_geometry.is_irreducible_of_is_integral
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "CommRing.of", "CommRing.prod_fan_is_limit", "by_contradiction", "false_of_nontrivial_of_product_domain", "irreducible_space", "is_integral", "is_preirreducible", "is_preirreducible_iff_closed_union_closed", "not_forall", "not_or_distrib" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_integral_of_is_irreducible_is_reduced [is_reduced X] [H : irreducible_space X.carrier] : is_integral X
begin split, intros U hU, haveI := (@@LocallyRingedSpace.component_nontrivial X.to_LocallyRingedSpace U hU).1, haveI : no_zero_divisors (X.to_LocallyRingedSpace.to_SheafedSpace.to_PresheafedSpace.presheaf.obj (op U)), { refine ⟨λ a b e, _⟩, simp_rw [← basic_open_eq_bot_iff, ← opens.not_nonempty_iff_eq_b...
lemma
algebraic_geometry.is_integral_of_is_irreducible_is_reduced
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "irreducible_space", "is_integral", "is_reduced", "no_zero_divisors", "no_zero_divisors.to_is_domain", "nonempty_preirreducible_inter", "ring_hom.map_mul", "ring_hom.map_zero", "zero_ne_one'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_integral_iff_is_irreducible_and_is_reduced : is_integral X ↔ irreducible_space X.carrier ∧ is_reduced X
⟨λ _, by exactI ⟨infer_instance, infer_instance⟩, λ ⟨_, _⟩, by exactI is_integral_of_is_irreducible_is_reduced X⟩
lemma
algebraic_geometry.is_integral_iff_is_irreducible_and_is_reduced
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "irreducible_space", "is_integral", "is_reduced" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_integral_of_open_immersion {X Y : Scheme} (f : X ⟶ Y) [H : is_open_immersion f] [is_integral Y] [nonempty X.carrier] : is_integral X
begin constructor, intros U hU, have : U = (opens.map f.1.base).obj (H.base_open.is_open_map.functor.obj U), { ext1, exact (set.preimage_image_eq _ H.base_open.inj).symm }, rw this, haveI : is_domain (Y.presheaf.obj (op (H.base_open.is_open_map.functor.obj U))), { apply_with is_integral.component_integral...
lemma
algebraic_geometry.is_integral_of_open_immersion
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_domain", "is_integral", "set.preimage_image_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
affine_is_integral_iff (R : CommRing) : is_integral (Scheme.Spec.obj $ op R) ↔ is_domain R
⟨λ h, by exactI ring_equiv.is_domain ((Scheme.Spec.obj $ op R).presheaf.obj _) (as_iso $ to_Spec_Γ R).CommRing_iso_to_ring_equiv, λ h, by exactI infer_instance⟩
lemma
algebraic_geometry.affine_is_integral_iff
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "CommRing", "is_domain", "is_integral", "ring_equiv.is_domain" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_integral_of_is_affine_is_domain [is_affine X] [nonempty X.carrier] [h : is_domain (X.presheaf.obj (op ⊤))] : is_integral X
begin haveI : is_integral (Scheme.Spec.obj (op (Scheme.Γ.obj (op X)))), { rw affine_is_integral_iff, exact h }, exact is_integral_of_open_immersion X.iso_Spec.hom, end
lemma
algebraic_geometry.is_integral_of_is_affine_is_domain
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_domain", "is_integral" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_injective_of_is_integral [is_integral X] {U V : opens X.carrier} (i : U ⟶ V) [H : nonempty U] : function.injective (X.presheaf.map i.op)
begin rw injective_iff_map_eq_zero, intros x hx, rw ← basic_open_eq_bot_iff at ⊢ hx, rw Scheme.basic_open_res at hx, revert hx, contrapose!, simp_rw [← opens.not_nonempty_iff_eq_bot, not_not], apply nonempty_preirreducible_inter U.is_open (RingedSpace.basic_open _ _).is_open, simpa using H end
lemma
algebraic_geometry.map_injective_of_is_integral
algebraic_geometry
src/algebraic_geometry/properties.lean
[ "algebraic_geometry.AffineScheme", "ring_theory.nilpotent", "topology.sheaves.sheaf_condition.sites", "algebra.category.Ring.constructions", "ring_theory.local_properties" ]
[ "is_integral", "is_open", "nonempty_preirreducible_inter", "not_not" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
V (i j : 𝒰.J) : Scheme
pullback ((pullback.fst : pullback ((𝒰.map i) ≫ f) g ⟶ _) ≫ (𝒰.map i)) (𝒰.map j)
def
algebraic_geometry.Scheme.pullback.V
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The intersection of `Uᵢ ×[Z] Y` and `Uⱼ ×[Z] Y` is given by (Uᵢ ×[Z] Y) ×[X] Uⱼ
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t (i j : 𝒰.J) : V 𝒰 f g i j ⟶ V 𝒰 f g j i
begin haveI : has_pullback (pullback.snd ≫ 𝒰.map i ≫ f) g := has_pullback_assoc_symm (𝒰.map j) (𝒰.map i) (𝒰.map i ≫ f) g, haveI : has_pullback (pullback.snd ≫ 𝒰.map j ≫ f) g := has_pullback_assoc_symm (𝒰.map i) (𝒰.map j) (𝒰.map j ≫ f) g, refine (pullback_symmetry _ _).hom ≫ _, refine (pullback_a...
def
algebraic_geometry.Scheme.pullback.t
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The canonical transition map `(Uᵢ ×[Z] Y) ×[X] Uⱼ ⟶ (Uⱼ ×[Z] Y) ×[X] Uᵢ` given by the fact that pullbacks are associative and symmetric.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t_fst_fst (i j : 𝒰.J) : t 𝒰 f g i j ≫ pullback.fst ≫ pullback.fst = pullback.snd
begin delta t, simp only [category.assoc, id.def, pullback_symmetry_hom_comp_fst_assoc, pullback_assoc_hom_snd_fst, pullback.lift_fst_assoc, pullback_symmetry_hom_comp_snd, pullback_assoc_inv_fst_fst, pullback_symmetry_hom_comp_fst], end
lemma
algebraic_geometry.Scheme.pullback.t_fst_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t_fst_snd (i j : 𝒰.J) : t 𝒰 f g i j ≫ pullback.fst ≫ pullback.snd = pullback.fst ≫ pullback.snd
begin delta t, simp only [pullback_symmetry_hom_comp_snd_assoc, category.comp_id, category.assoc, id.def, pullback_symmetry_hom_comp_fst_assoc, pullback_assoc_hom_snd_snd, pullback.lift_snd, pullback_assoc_inv_snd], end
lemma
algebraic_geometry.Scheme.pullback.t_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t_snd (i j : 𝒰.J) : t 𝒰 f g i j ≫ pullback.snd = pullback.fst ≫ pullback.fst
begin delta t, simp only [pullback_symmetry_hom_comp_snd_assoc, category.assoc, id.def, pullback_symmetry_hom_comp_snd, pullback_assoc_hom_fst, pullback.lift_fst_assoc, pullback_symmetry_hom_comp_fst, pullback_assoc_inv_fst_snd], end
lemma
algebraic_geometry.Scheme.pullback.t_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t_id (i : 𝒰.J) : t 𝒰 f g i i = 𝟙 _
begin apply pullback.hom_ext; rw category.id_comp, apply pullback.hom_ext, { rw ← cancel_mono (𝒰.map i), simp only [pullback.condition, category.assoc, t_fst_fst] }, { simp only [category.assoc, t_fst_snd]}, { rw ← cancel_mono (𝒰.map i),simp only [pullback.condition, t_snd, category.assoc] } end
lemma
algebraic_geometry.Scheme.pullback.t_id
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fV (i j : 𝒰.J) : V 𝒰 f g i j ⟶ pullback ((𝒰.map i) ≫ f) g
pullback.fst
abbreviation
algebraic_geometry.Scheme.pullback.fV
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The inclusion map of `V i j = (Uᵢ ×[Z] Y) ×[X] Uⱼ ⟶ Uᵢ ×[Z] Y`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t' (i j k : 𝒰.J) : pullback (fV 𝒰 f g i j) (fV 𝒰 f g i k) ⟶ pullback (fV 𝒰 f g j k) (fV 𝒰 f g j i)
begin refine (pullback_right_pullback_fst_iso _ _ _).hom ≫ _, refine _ ≫ (pullback_symmetry _ _).hom, refine _ ≫ (pullback_right_pullback_fst_iso _ _ _).inv, refine pullback.map _ _ _ _ (t 𝒰 f g i j) (𝟙 _) (𝟙 _) _ _, { simp only [←pullback.condition, category.comp_id, t_fst_fst_assoc] }, { simp only [cat...
def
algebraic_geometry.Scheme.pullback.t'
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The map `((Xᵢ ×[Z] Y) ×[X] Xⱼ) ×[Xᵢ ×[Z] Y] ((Xᵢ ×[Z] Y) ×[X] Xₖ)` ⟶ `((Xⱼ ×[Z] Y) ×[X] Xₖ) ×[Xⱼ ×[Z] Y] ((Xⱼ ×[Z] Y) ×[X] Xᵢ)` needed for gluing
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t'_fst_fst_fst (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ pullback.fst ≫ pullback.fst ≫ pullback.fst = pullback.fst ≫ pullback.snd
begin delta t', simp only [category.assoc, pullback_symmetry_hom_comp_fst_assoc, pullback_right_pullback_fst_iso_inv_snd_fst_assoc, pullback.lift_fst_assoc, t_fst_fst, pullback_right_pullback_fst_iso_hom_fst_assoc], end
lemma
algebraic_geometry.Scheme.pullback.t'_fst_fst_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t'_fst_fst_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ pullback.fst ≫ pullback.fst ≫ pullback.snd = pullback.fst ≫ pullback.fst ≫ pullback.snd
begin delta t', simp only [category.assoc, pullback_symmetry_hom_comp_fst_assoc, pullback_right_pullback_fst_iso_inv_snd_fst_assoc, pullback.lift_fst_assoc, t_fst_snd, pullback_right_pullback_fst_iso_hom_fst_assoc], end
lemma
algebraic_geometry.Scheme.pullback.t'_fst_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t'_fst_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ pullback.fst ≫ pullback.snd = pullback.snd ≫ pullback.snd
begin delta t', simp only [category.comp_id, category.assoc, pullback_symmetry_hom_comp_fst_assoc, pullback_right_pullback_fst_iso_inv_snd_snd, pullback.lift_snd, pullback_right_pullback_fst_iso_hom_snd], end
lemma
algebraic_geometry.Scheme.pullback.t'_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t'_snd_fst_fst (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ pullback.snd ≫ pullback.fst ≫ pullback.fst = pullback.fst ≫ pullback.snd
begin delta t', simp only [category.assoc, pullback_symmetry_hom_comp_snd_assoc, pullback_right_pullback_fst_iso_inv_fst_assoc, pullback.lift_fst_assoc, t_fst_fst, pullback_right_pullback_fst_iso_hom_fst_assoc], end
lemma
algebraic_geometry.Scheme.pullback.t'_snd_fst_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t'_snd_fst_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ pullback.snd ≫ pullback.fst ≫ pullback.snd = pullback.fst ≫ pullback.fst ≫ pullback.snd
begin delta t', simp only [category.assoc, pullback_symmetry_hom_comp_snd_assoc, pullback_right_pullback_fst_iso_inv_fst_assoc, pullback.lift_fst_assoc, t_fst_snd, pullback_right_pullback_fst_iso_hom_fst_assoc], end
lemma
algebraic_geometry.Scheme.pullback.t'_snd_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
t'_snd_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ pullback.snd ≫ pullback.snd = pullback.fst ≫ pullback.fst ≫ pullback.fst
begin delta t', simp only [category.assoc, pullback_symmetry_hom_comp_snd_assoc, pullback_right_pullback_fst_iso_inv_fst_assoc, pullback.lift_fst_assoc, t_snd, pullback_right_pullback_fst_iso_hom_fst_assoc], end
lemma
algebraic_geometry.Scheme.pullback.t'_snd_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle_fst_fst_fst (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.fst ≫ pullback.fst ≫ pullback.fst = pullback.fst ≫ pullback.fst ≫ pullback.fst
by simp only [t'_fst_fst_fst, t'_fst_snd, t'_snd_snd]
lemma
algebraic_geometry.Scheme.pullback.cocycle_fst_fst_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle_fst_fst_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.fst ≫ pullback.fst ≫ pullback.snd = pullback.fst ≫ pullback.fst ≫ pullback.snd
by simp only [t'_fst_fst_snd]
lemma
algebraic_geometry.Scheme.pullback.cocycle_fst_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle_fst_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.fst ≫ pullback.snd = pullback.fst ≫ pullback.snd
by simp only [t'_fst_snd, t'_snd_snd, t'_fst_fst_fst]
lemma
algebraic_geometry.Scheme.pullback.cocycle_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle_snd_fst_fst (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.snd ≫ pullback.fst ≫ pullback.fst = pullback.snd ≫ pullback.fst ≫ pullback.fst
begin rw ← cancel_mono (𝒰.map i), simp only [pullback.condition_assoc, t'_snd_fst_fst, t'_fst_snd, t'_snd_snd] end
lemma
algebraic_geometry.Scheme.pullback.cocycle_snd_fst_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle_snd_fst_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.snd ≫ pullback.fst ≫ pullback.snd = pullback.snd ≫ pullback.fst ≫ pullback.snd
by simp only [pullback.condition_assoc, t'_snd_fst_snd]
lemma
algebraic_geometry.Scheme.pullback.cocycle_snd_fst_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle_snd_snd (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.snd ≫ pullback.snd = pullback.snd ≫ pullback.snd
by simp only [t'_snd_snd, t'_fst_fst_fst, t'_fst_snd]
lemma
algebraic_geometry.Scheme.pullback.cocycle_snd_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocycle (i j k : 𝒰.J) : t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j = 𝟙 _
begin apply pullback.hom_ext; rw category.id_comp, { apply pullback.hom_ext, { apply pullback.hom_ext, { simp_rw category.assoc, exact cocycle_fst_fst_fst 𝒰 f g i j k }, { simp_rw category.assoc, exact cocycle_fst_fst_snd 𝒰 f g i j k } }, { simp_rw category.assoc, exact c...
lemma
algebraic_geometry.Scheme.pullback.cocycle
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gluing : Scheme.glue_data.{u}
{ J := 𝒰.J, U := λ i, pullback ((𝒰.map i) ≫ f) g, V := λ ⟨i, j⟩, V 𝒰 f g i j, -- `p⁻¹(Uᵢ ∩ Uⱼ)` where `p : Uᵢ ×[Z] Y ⟶ Uᵢ ⟶ X`. f := λ i j, pullback.fst, f_id := λ i, infer_instance, f_open := infer_instance, t := λ i j, t 𝒰 f g i j, t_id := λ i, t_id 𝒰 f g i, t' := λ i j k, t' 𝒰 f g i j k, t_fa...
def
algebraic_geometry.Scheme.pullback.gluing
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
Given `Uᵢ ×[Z] Y`, this is the glued fibered product `X ×[Z] Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p1 : (gluing 𝒰 f g).glued ⟶ X
begin fapply multicoequalizer.desc, exact λ i, pullback.fst ≫ 𝒰.map i, rintro ⟨i, j⟩, change pullback.fst ≫ _ ≫ 𝒰.map i = (_ ≫ _) ≫ _ ≫ 𝒰.map j, rw pullback.condition, rw ← category.assoc, congr' 1, rw category.assoc, exact (t_fst_fst _ _ _ _ _).symm end
def
algebraic_geometry.Scheme.pullback.p1
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The first projection from the glued scheme into `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p2 : (gluing 𝒰 f g).glued ⟶ Y
begin fapply multicoequalizer.desc, exact λ i, pullback.snd, rintro ⟨i, j⟩, change pullback.fst ≫ _ = (_ ≫ _) ≫ _, rw category.assoc, exact (t_fst_snd _ _ _ _ _).symm end
def
algebraic_geometry.Scheme.pullback.p2
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The second projection from the glued scheme into `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p_comm : p1 𝒰 f g ≫ f = p2 𝒰 f g ≫ g
begin apply multicoequalizer.hom_ext, intro i, erw [multicoequalizer.π_desc_assoc, multicoequalizer.π_desc_assoc], rw [category.assoc, pullback.condition] end
lemma
algebraic_geometry.Scheme.pullback.p_comm
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_lift_pullback_map (i j : 𝒰.J) : pullback ((𝒰.pullback_cover s.fst).map i) ((𝒰.pullback_cover s.fst).map j) ⟶ (gluing 𝒰 f g).V ⟨i, j⟩
begin change pullback pullback.fst pullback.fst ⟶ pullback _ _, refine (pullback_right_pullback_fst_iso _ _ _).hom ≫ _, refine pullback.map _ _ _ _ _ (𝟙 _) (𝟙 _) _ _, { exact (pullback_symmetry _ _).hom ≫ pullback.map _ _ _ _ (𝟙 _) s.snd f (category.id_comp _).symm s.condition }, { simpa using pullba...
def
algebraic_geometry.Scheme.pullback.glued_lift_pullback_map
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
(Implementation) The canonical map `(s.X ×[X] Uᵢ) ×[s.X] (s.X ×[X] Uⱼ) ⟶ (Uᵢ ×[Z] Y) ×[X] Uⱼ` This is used in `glued_lift`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_lift_pullback_map_fst (i j : 𝒰.J) : glued_lift_pullback_map 𝒰 f g s i j ≫ pullback.fst = pullback.fst ≫ (pullback_symmetry _ _).hom ≫ pullback.map _ _ _ _ (𝟙 _) s.snd f (category.id_comp _).symm s.condition
begin delta glued_lift_pullback_map, simp only [category.assoc, id.def, pullback.lift_fst, pullback_right_pullback_fst_iso_hom_fst_assoc], end
lemma
algebraic_geometry.Scheme.pullback.glued_lift_pullback_map_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_lift_pullback_map_snd (i j : 𝒰.J) : glued_lift_pullback_map 𝒰 f g s i j ≫ pullback.snd = pullback.snd ≫ pullback.snd
begin delta glued_lift_pullback_map, simp only [category.assoc, category.comp_id, id.def, pullback.lift_snd, pullback_right_pullback_fst_iso_hom_snd], end
lemma
algebraic_geometry.Scheme.pullback.glued_lift_pullback_map_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_lift : s.X ⟶ (gluing 𝒰 f g).glued
begin fapply (𝒰.pullback_cover s.fst).glue_morphisms, { exact λ i, (pullback_symmetry _ _).hom ≫ pullback.map _ _ _ _ (𝟙 _) s.snd f (category.id_comp _).symm s.condition ≫ (gluing 𝒰 f g).ι i }, intros i j, rw ← glued_lift_pullback_map_fst_assoc, have : _ = pullback.fst ≫ _ := (gluing 𝒰 f g).gl...
def
algebraic_geometry.Scheme.pullback.glued_lift
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The lifted map `s.X ⟶ (gluing 𝒰 f g).glued` in order to show that `(gluing 𝒰 f g).glued` is indeed the pullback. Given a pullback cone `s`, we have the maps `s.fst ⁻¹' Uᵢ ⟶ Uᵢ` and `s.fst ⁻¹' Uᵢ ⟶ s.X ⟶ Y` that we may lift to a map `s.fst ⁻¹' Uᵢ ⟶ Uᵢ ×[Z] Y`. to glue these into a map `s.X ⟶ Uᵢ ×[Z] Y`, we need to s...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_lift_p1 : glued_lift 𝒰 f g s ≫ p1 𝒰 f g = s.fst
begin rw ← cancel_epi (𝒰.pullback_cover s.fst).from_glued, apply multicoequalizer.hom_ext, intro b, erw [multicoequalizer.π_desc_assoc, multicoequalizer.π_desc_assoc], delta glued_lift, simp_rw ← category.assoc, rw (𝒰.pullback_cover s.fst).ι_glue_morphisms, simp_rw category.assoc, erw [multicoequali...
lemma
algebraic_geometry.Scheme.pullback.glued_lift_p1
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_lift_p2 : glued_lift 𝒰 f g s ≫ p2 𝒰 f g = s.snd
begin rw ← cancel_epi (𝒰.pullback_cover s.fst).from_glued, apply multicoequalizer.hom_ext, intro b, erw [multicoequalizer.π_desc_assoc, multicoequalizer.π_desc_assoc], delta glued_lift, simp_rw ← category.assoc, rw (𝒰.pullback_cover s.fst).ι_glue_morphisms, simp_rw category.assoc, erw [multicoequali...
lemma
algebraic_geometry.Scheme.pullback.glued_lift_p2
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_fst_ι_to_V (i j : 𝒰.J) : pullback (pullback.fst : pullback (p1 𝒰 f g) (𝒰.map i) ⟶ _) ((gluing 𝒰 f g).ι j) ⟶ V 𝒰 f g j i
(pullback_symmetry _ _ ≪≫ (pullback_right_pullback_fst_iso (p1 𝒰 f g) (𝒰.map i) _)).hom ≫ (pullback.congr_hom (multicoequalizer.π_desc _ _ _ _ _) rfl).hom
def
algebraic_geometry.Scheme.pullback.pullback_fst_ι_to_V
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
(Implementation) The canonical map `(W ×[X] Uᵢ) ×[W] (Uⱼ ×[Z] Y) ⟶ (Uⱼ ×[Z] Y) ×[X] Uᵢ = V j i` where `W` is the glued fibred product. This is used in `lift_comp_ι`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_fst_ι_to_V_fst (i j : 𝒰.J) : pullback_fst_ι_to_V 𝒰 f g i j ≫ pullback.fst = pullback.snd
begin delta pullback_fst_ι_to_V, simp only [iso.trans_hom, pullback.congr_hom_hom, category.assoc, pullback.lift_fst, category.comp_id, pullback_right_pullback_fst_iso_hom_fst, pullback_symmetry_hom_comp_fst], end
lemma
algebraic_geometry.Scheme.pullback.pullback_fst_ι_to_V_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_fst_ι_to_V_snd (i j : 𝒰.J) : pullback_fst_ι_to_V 𝒰 f g i j ≫ pullback.snd = pullback.fst ≫ pullback.snd
begin delta pullback_fst_ι_to_V, simp only [iso.trans_hom, pullback.congr_hom_hom, category.assoc, pullback.lift_snd, category.comp_id, pullback_right_pullback_fst_iso_hom_snd, pullback_symmetry_hom_comp_snd_assoc] end
lemma
algebraic_geometry.Scheme.pullback.pullback_fst_ι_to_V_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lift_comp_ι (i : 𝒰.J) : pullback.lift pullback.snd (pullback.fst ≫ p2 𝒰 f g) (by rw [← pullback.condition_assoc, category.assoc, p_comm]) ≫ (gluing 𝒰 f g).ι i = (pullback.fst : pullback (p1 𝒰 f g) (𝒰.map i) ⟶ _)
begin apply ((gluing 𝒰 f g).open_cover.pullback_cover pullback.fst).hom_ext, intro j, dsimp only [open_cover.pullback_cover], transitivity pullback_fst_ι_to_V 𝒰 f g i j ≫ fV 𝒰 f g j i ≫ (gluing 𝒰 f g).ι _, { rw ← (show _ = fV 𝒰 f g j i ≫ _, from (gluing 𝒰 f g).glue_condition j i), simp_rw ← category...
lemma
algebraic_geometry.Scheme.pullback.lift_comp_ι
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "hom_ext" ]
We show that the map `W ×[X] Uᵢ ⟶ Uᵢ ×[Z] Y ⟶ W` is the first projection, where the first map is given by the lift of `W ×[X] Uᵢ ⟶ Uᵢ` and `W ×[X] Uᵢ ⟶ W ⟶ Y`. It suffices to show that the two map agrees when restricted onto `Uⱼ ×[Z] Y`. In this case, both maps factor through `V j i` via `pullback_fst_ι_to_V`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_p1_iso (i : 𝒰.J) : pullback (p1 𝒰 f g) (𝒰.map i) ≅ pullback (𝒰.map i ≫ f) g
begin fsplit, exact pullback.lift pullback.snd (pullback.fst ≫ p2 𝒰 f g) (by rw [← pullback.condition_assoc, category.assoc, p_comm]), refine pullback.lift ((gluing 𝒰 f g).ι i) pullback.fst (by erw multicoequalizer.π_desc), { apply pullback.hom_ext, { simpa using lift_comp_ι 𝒰 f g i }, { simp...
def
algebraic_geometry.Scheme.pullback.pullback_p1_iso
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
The canonical isomorphism between `W ×[X] Uᵢ` and `Uᵢ ×[X] Y`. That is, the preimage of `Uᵢ` in `W` along `p1` is indeed `Uᵢ ×[X] Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_p1_iso_hom_fst (i : 𝒰.J) : (pullback_p1_iso 𝒰 f g i).hom ≫ pullback.fst = pullback.snd
by { delta pullback_p1_iso, simp only [pullback.lift_fst] }
lemma
algebraic_geometry.Scheme.pullback.pullback_p1_iso_hom_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_p1_iso_hom_snd (i : 𝒰.J) : (pullback_p1_iso 𝒰 f g i).hom ≫ pullback.snd = pullback.fst ≫ p2 𝒰 f g
by { delta pullback_p1_iso, simp only [pullback.lift_snd] }
lemma
algebraic_geometry.Scheme.pullback.pullback_p1_iso_hom_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_p1_iso_inv_fst (i : 𝒰.J) : (pullback_p1_iso 𝒰 f g i).inv ≫ pullback.fst = (gluing 𝒰 f g).ι i
by { delta pullback_p1_iso, simp only [pullback.lift_fst] }
lemma
algebraic_geometry.Scheme.pullback.pullback_p1_iso_inv_fst
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_p1_iso_inv_snd (i : 𝒰.J) : (pullback_p1_iso 𝒰 f g i).inv ≫ pullback.snd = pullback.fst
by { delta pullback_p1_iso, simp only [pullback.lift_snd] }
lemma
algebraic_geometry.Scheme.pullback.pullback_p1_iso_inv_snd
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_p1_iso_hom_ι (i : 𝒰.J) : (pullback_p1_iso 𝒰 f g i).hom ≫ (gluing 𝒰 f g).ι i = pullback.fst
by rw [← pullback_p1_iso_inv_fst, iso.hom_inv_id_assoc]
lemma
algebraic_geometry.Scheme.pullback.pullback_p1_iso_hom_ι
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glued_is_limit : is_limit (pullback_cone.mk _ _ (p_comm 𝒰 f g))
begin apply pullback_cone.is_limit_aux', intro s, refine ⟨glued_lift 𝒰 f g s, glued_lift_p1 𝒰 f g s, glued_lift_p2 𝒰 f g s, _⟩, intros m h₁ h₂, change m ≫ p1 𝒰 f g = _ at h₁, change m ≫ p2 𝒰 f g = _ at h₂, apply (𝒰.pullback_cover s.fst).hom_ext, intro i, rw open_cover.pullback_cover_map, have ...
def
algebraic_geometry.Scheme.pullback.glued_is_limit
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "hom_ext" ]
The glued scheme (`(gluing 𝒰 f g).glued`) is indeed the pullback of `f` and `g`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_pullback_of_cover : has_pullback f g
⟨⟨⟨_, glued_is_limit 𝒰 f g⟩⟩⟩
lemma
algebraic_geometry.Scheme.pullback.has_pullback_of_cover
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
affine_has_pullback {A B C : CommRing} (f : Spec.obj (opposite.op A) ⟶ Spec.obj (opposite.op C)) (g : Spec.obj (opposite.op B) ⟶ Spec.obj (opposite.op C)) : has_pullback f g
begin rw [← Spec.image_preimage f, ← Spec.image_preimage g], exact ⟨⟨⟨_,is_limit_of_has_pullback_of_preserves_limit Spec (Spec.preimage f) (Spec.preimage g)⟩⟩⟩ end
instance
algebraic_geometry.Scheme.pullback.affine_has_pullback
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "CommRing", "opposite.op" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
affine_affine_has_pullback {B C : CommRing} {X : Scheme} (f : X ⟶ Spec.obj (opposite.op C)) (g : Spec.obj (opposite.op B) ⟶ Spec.obj (opposite.op C)) : has_pullback f g
has_pullback_of_cover X.affine_cover f g
lemma
algebraic_geometry.Scheme.pullback.affine_affine_has_pullback
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "CommRing", "opposite.op" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
base_affine_has_pullback {C : CommRing} {X Y : Scheme} (f : X ⟶ Spec.obj (opposite.op C)) (g : Y ⟶ Spec.obj (opposite.op C)) : has_pullback f g
@@has_pullback_symmetry _ _ _ (@@has_pullback_of_cover Y.affine_cover g f (λ i, @@has_pullback_symmetry _ _ _ $ affine_affine_has_pullback _ _))
instance
algebraic_geometry.Scheme.pullback.base_affine_has_pullback
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "CommRing", "opposite.op" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_affine_comp_pullback_has_pullback {X Y Z : Scheme} (f : X ⟶ Z) (g : Y ⟶ Z) (i : Z.affine_cover.J) : has_pullback ((Z.affine_cover.pullback_cover f).map i ≫ f) g
begin let Xᵢ := pullback f (Z.affine_cover.map i), let Yᵢ := pullback g (Z.affine_cover.map i), let W := pullback (pullback.snd : Yᵢ ⟶ _) (pullback.snd : Xᵢ ⟶ _), have := big_square_is_pullback (pullback.fst : W ⟶ _) (pullback.fst : Yᵢ ⟶ _) (pullback.snd : Xᵢ ⟶ _) (Z.affine_cover.map i) pullback.snd pullbac...
instance
algebraic_geometry.Scheme.pullback.left_affine_comp_pullback_has_pullback
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_cover_of_left (𝒰 : open_cover X) (f : X ⟶ Z) (g : Y ⟶ Z) : open_cover (pullback f g)
begin fapply ((gluing 𝒰 f g).open_cover.pushforward_iso (limit.iso_limit_cone ⟨_, glued_is_limit 𝒰 f g⟩).inv).copy 𝒰.J (λ i, pullback (𝒰.map i ≫ f) g) (λ i, pullback.map _ _ _ _ (𝒰.map i) (𝟙 _) (𝟙 _) (category.comp_id _) (by simp)) (equiv.refl 𝒰.J) (λ _, iso.refl _), rintro (i : 𝒰.J), cha...
def
algebraic_geometry.Scheme.pullback.open_cover_of_left
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "equiv.refl" ]
Given an open cover `{ Xᵢ }` of `X`, then `X ×[Z] Y` is covered by `Xᵢ ×[Z] Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_cover_of_right (𝒰 : open_cover Y) (f : X ⟶ Z) (g : Y ⟶ Z) : open_cover (pullback f g)
begin fapply ((open_cover_of_left 𝒰 g f).pushforward_iso (pullback_symmetry _ _).hom).copy 𝒰.J (λ i, pullback f (𝒰.map i ≫ g)) (λ i, pullback.map _ _ _ _ (𝟙 _) (𝒰.map i) (𝟙 _) (by simp) (category.comp_id _)) (equiv.refl _) (λ i, pullback_symmetry _ _), intro i, dsimp [open_cover.bind], apply p...
def
algebraic_geometry.Scheme.pullback.open_cover_of_right
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "equiv.refl" ]
Given an open cover `{ Yᵢ }` of `Y`, then `X ×[Z] Y` is covered by `X ×[Z] Yᵢ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_cover_of_left_right (𝒰X : X.open_cover) (𝒰Y : Y.open_cover) (f : X ⟶ Z) (g : Y ⟶ Z) : (pullback f g).open_cover
begin fapply ((open_cover_of_left 𝒰X f g).bind (λ x, open_cover_of_right 𝒰Y (𝒰X.map x ≫ f) g)).copy (𝒰X.J × 𝒰Y.J) (λ ij, pullback (𝒰X.map ij.1 ≫ f) (𝒰Y.map ij.2 ≫ g)) (λ ij, pullback.map _ _ _ _ (𝒰X.map ij.1) (𝒰Y.map ij.2) (𝟙 _) (category.comp_id _) (category.comp_id _)) (equiv.sigma_e...
def
algebraic_geometry.Scheme.pullback.open_cover_of_left_right
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "equiv.sigma_equiv_prod" ]
Given an open cover `{ Xᵢ }` of `X` and an open cover `{ Yⱼ }` of `Y`, then `X ×[Z] Y` is covered by `Xᵢ ×[Z] Yⱼ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_cover_of_base' (𝒰 : open_cover Z) (f : X ⟶ Z) (g : Y ⟶ Z) : open_cover (pullback f g)
begin apply (open_cover_of_left (𝒰.pullback_cover f) f g).bind, intro i, let Xᵢ := pullback f (𝒰.map i), let Yᵢ := pullback g (𝒰.map i), let W := pullback (pullback.snd : Yᵢ ⟶ _) (pullback.snd : Xᵢ ⟶ _), have := big_square_is_pullback (pullback.fst : W ⟶ _) (pullback.fst : Yᵢ ⟶ _) (pullback.snd : Xᵢ ...
def
algebraic_geometry.Scheme.pullback.open_cover_of_base'
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[]
(Implementation). Use `open_cover_of_base` instead.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_cover_of_base (𝒰 : open_cover Z) (f : X ⟶ Z) (g : Y ⟶ Z) : open_cover (pullback f g)
begin apply (open_cover_of_base' 𝒰 f g).copy 𝒰.J (λ i, pullback (pullback.snd : pullback f (𝒰.map i) ⟶ _) (pullback.snd : pullback g (𝒰.map i) ⟶ _)) (λ i, pullback.map _ _ _ _ pullback.fst pullback.fst (𝒰.map i) pullback.condition.symm pullback.condition.symm) ((equiv.prod_punit 𝒰.J)...
def
algebraic_geometry.Scheme.pullback.open_cover_of_base
algebraic_geometry
src/algebraic_geometry/pullbacks.lean
[ "algebraic_geometry.gluing", "category_theory.limits.opposites", "algebraic_geometry.AffineScheme", "category_theory.limits.shapes.diagonal" ]
[ "equiv.prod_punit", "equiv.sigma_equiv_prod" ]
Given an open cover `{ Zᵢ }` of `Z`, then `X ×[Z] Y` is covered by `Xᵢ ×[Zᵢ] Yᵢ`, where `Xᵢ = X ×[Z] Zᵢ` and `Yᵢ = Y ×[Z] Zᵢ` is the preimage of `Zᵢ` in `X` and `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
RingedSpace : Type*
SheafedSpace CommRing
abbreviation
algebraic_geometry.RingedSpace
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "CommRing" ]
The type of Ringed spaces, as an abbreviation for `SheafedSpace CommRing`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit_res_of_is_unit_germ (U : opens X) (f : X.presheaf.obj (op U)) (x : U) (h : is_unit (X.presheaf.germ x f)) : ∃ (V : opens X) (i : V ⟶ U) (hxV : x.1 ∈ V), is_unit (X.presheaf.map i.op f)
begin obtain ⟨g', heq⟩ := h.exists_right_inv, obtain ⟨V, hxV, g, rfl⟩ := X.presheaf.germ_exist x.1 g', let W := U ⊓ V, have hxW : x.1 ∈ W := ⟨x.2, hxV⟩, erw [← X.presheaf.germ_res_apply (opens.inf_le_left U V) ⟨x.1, hxW⟩ f, ← X.presheaf.germ_res_apply (opens.inf_le_right U V) ⟨x.1, hxW⟩ g, ← ring_hom....
lemma
algebraic_geometry.RingedSpace.is_unit_res_of_is_unit_germ
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "is_unit", "is_unit_of_mul_eq_one", "ring_hom.map_mul", "ring_hom.map_one" ]
If the germ of a section `f` is a unit in the stalk at `x`, then `f` must be a unit on some small neighborhood around `x`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit_of_is_unit_germ (U : opens X) (f : X.presheaf.obj (op U)) (h : ∀ x : U, is_unit (X.presheaf.germ x f)) : is_unit f
begin -- We pick a cover of `U` by open sets `V x`, such that `f` is a unit on each `V x`. choose V iVU m h_unit using λ x : U, X.is_unit_res_of_is_unit_germ U f x (h x), have hcover : U ≤ supr V, { intros x hxU, rw [opens.mem_supr], exact ⟨⟨x, hxU⟩, m ⟨x, hxU⟩⟩ }, -- Let `g x` denote the inverse of `...
lemma
algebraic_geometry.RingedSpace.is_unit_of_is_unit_germ
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "is_unit", "is_unit.exists_right_inv", "is_unit.mul_right_inj", "is_unit_of_mul_eq_one", "ring_hom.map_mul", "ring_hom.map_one", "supr" ]
If a section `f` is a unit in each stalk, `f` must be a unit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
basic_open {U : opens X} (f : X.presheaf.obj (op U)) : opens X
{ carrier := coe '' { x : U | is_unit (X.presheaf.germ x f) }, is_open' := begin rw is_open_iff_forall_mem_open, rintros _ ⟨x, hx, rfl⟩, obtain ⟨V, i, hxV, hf⟩ := X.is_unit_res_of_is_unit_germ U f x hx, use V.1, refine ⟨_, V.2, hxV⟩, intros y hy, use (⟨y, i.le hy⟩ : U), rw set.mem_set_...
def
algebraic_geometry.RingedSpace.basic_open
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "is_open_iff_forall_mem_open", "is_unit", "ring_hom.is_unit_map" ]
The basic open of a section `f` is the set of all points `x`, such that the germ of `f` at `x` is a unit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_basic_open {U : opens X} (f : X.presheaf.obj (op U)) (x : U) : ↑x ∈ X.basic_open f ↔ is_unit (X.presheaf.germ x f)
begin split, { rintro ⟨x, hx, a⟩, cases subtype.eq a, exact hx }, { intro h, exact ⟨x, h, rfl⟩ }, end
lemma
algebraic_geometry.RingedSpace.mem_basic_open
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "is_unit" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_top_basic_open (f : X.presheaf.obj (op ⊤)) (x : X) : x ∈ X.basic_open f ↔ is_unit (X.presheaf.germ ⟨x, show x ∈ (⊤ : opens X), by trivial⟩ f)
mem_basic_open X f ⟨x, _⟩
lemma
algebraic_geometry.RingedSpace.mem_top_basic_open
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "is_unit" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
basic_open_le {U : opens X} (f : X.presheaf.obj (op U)) : X.basic_open f ≤ U
by { rintros _ ⟨x, hx, rfl⟩, exact x.2 }
lemma
algebraic_geometry.RingedSpace.basic_open_le
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit_res_basic_open {U : opens X} (f : X.presheaf.obj (op U)) : is_unit (X.presheaf.map (@hom_of_le (opens X) _ _ _ (X.basic_open_le f)).op f)
begin apply is_unit_of_is_unit_germ, rintro ⟨_, ⟨x, hx, rfl⟩⟩, convert hx, rw germ_res_apply, refl, end
lemma
algebraic_geometry.RingedSpace.is_unit_res_basic_open
algebraic_geometry
src/algebraic_geometry/ringed_space.lean
[ "algebra.category.Ring.filtered_colimits", "algebraic_geometry.sheafed_space", "topology.sheaves.stalks", "algebra.category.Ring.colimits", "algebra.category.Ring.limits" ]
[ "is_unit" ]
The restriction of a section `f` to the basic open of `f` is a unit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83